t for space travel. The Incas stored their potatoes and other food crops on the mountain heights above Machu Picchu. The cold mountain temperatures froze the food and the water inside slowly vaporized under the low air pressure of the high altitudes.
Freeze-drying is method for preserving materials, which are unstable in solution. In addition, freeze-drying can be used to separate and recover volatile substances, and to purify materials. The fundamental process steps are:
Freezing: The produ